1  /* SPDX-License-Identifier: GPL-2.0 */
2  /* interrupt.h */
3  #ifndef _LINUX_INTERRUPT_H
4  #define _LINUX_INTERRUPT_H
5  
6  #include <linux/kernel.h>
7  #include <linux/bitops.h>
8  #include <linux/cleanup.h>
9  #include <linux/irqreturn.h>
10  #include <linux/irqnr.h>
11  #include <linux/hardirq.h>
12  #include <linux/irqflags.h>
13  #include <linux/hrtimer.h>
14  #include <linux/kref.h>
15  #include <linux/cpumask_types.h>
16  #include <linux/workqueue.h>
17  #include <linux/jump_label.h>
18  
19  #include <linux/atomic.h>
20  #include <asm/ptrace.h>
21  #include <asm/irq.h>
22  #include <asm/sections.h>
23  
24  /*
25   * These correspond to the IORESOURCE_IRQ_* defines in
26   * linux/ioport.h to select the interrupt line behaviour.  When
27   * requesting an interrupt without specifying a IRQF_TRIGGER, the
28   * setting should be assumed to be "as already configured", which
29   * may be as per machine or firmware initialisation.
30   */
31  #define IRQF_TRIGGER_NONE	0x00000000
32  #define IRQF_TRIGGER_RISING	0x00000001
33  #define IRQF_TRIGGER_FALLING	0x00000002
34  #define IRQF_TRIGGER_HIGH	0x00000004
35  #define IRQF_TRIGGER_LOW	0x00000008
36  #define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
37  				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
38  #define IRQF_TRIGGER_PROBE	0x00000010
39  
40  /*
41   * These flags used only by the kernel as part of the
42   * irq handling routines.
43   *
44   * IRQF_SHARED - allow sharing the irq among several devices
45   * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
46   * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
47   * IRQF_PERCPU - Interrupt is per cpu
48   * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
49   * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
50   *                registered first in a shared interrupt is considered for
51   *                performance reasons)
52   * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
53   *                Used by threaded interrupts which need to keep the
54   *                irq line disabled until the threaded handler has been run.
55   * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend.  Does not guarantee
56   *                   that this interrupt will wake the system from a suspended
57   *                   state.  See Documentation/power/suspend-and-interrupts.rst
58   * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
59   * IRQF_NO_THREAD - Interrupt cannot be threaded
60   * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
61   *                resume time.
62   * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
63   *                interrupt handler after suspending interrupts. For system
64   *                wakeup devices users need to implement wakeup detection in
65   *                their interrupt handlers.
66   * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.
67   *                Users will enable it explicitly by enable_irq() or enable_nmi()
68   *                later.
69   * IRQF_NO_DEBUG - Exclude from runnaway detection for IPI and similar handlers,
70   *		   depends on IRQF_PERCPU.
71   * IRQF_COND_ONESHOT - Agree to do IRQF_ONESHOT if already set for a shared
72   *                 interrupt.
73   */
74  #define IRQF_SHARED		0x00000080
75  #define IRQF_PROBE_SHARED	0x00000100
76  #define __IRQF_TIMER		0x00000200
77  #define IRQF_PERCPU		0x00000400
78  #define IRQF_NOBALANCING	0x00000800
79  #define IRQF_IRQPOLL		0x00001000
80  #define IRQF_ONESHOT		0x00002000
81  #define IRQF_NO_SUSPEND		0x00004000
82  #define IRQF_FORCE_RESUME	0x00008000
83  #define IRQF_NO_THREAD		0x00010000
84  #define IRQF_EARLY_RESUME	0x00020000
85  #define IRQF_COND_SUSPEND	0x00040000
86  #define IRQF_NO_AUTOEN		0x00080000
87  #define IRQF_NO_DEBUG		0x00100000
88  #define IRQF_COND_ONESHOT	0x00200000
89  
90  #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
91  
92  /*
93   * These values can be returned by request_any_context_irq() and
94   * describe the context the interrupt will be run in.
95   *
96   * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
97   * IRQC_IS_NESTED - interrupt runs in a nested threaded context
98   */
99  enum {
100  	IRQC_IS_HARDIRQ	= 0,
101  	IRQC_IS_NESTED,
102  };
103  
104  typedef irqreturn_t (*irq_handler_t)(int, void *);
105  
106  /**
107   * struct irqaction - per interrupt action descriptor
108   * @handler:	interrupt handler function
109   * @name:	name of the device
110   * @dev_id:	cookie to identify the device
111   * @percpu_dev_id:	cookie to identify the device
112   * @next:	pointer to the next irqaction for shared interrupts
113   * @irq:	interrupt number
114   * @flags:	flags (see IRQF_* above)
115   * @thread_fn:	interrupt handler function for threaded interrupts
116   * @thread:	thread pointer for threaded interrupts
117   * @secondary:	pointer to secondary irqaction (force threading)
118   * @thread_flags:	flags related to @thread
119   * @thread_mask:	bitmask for keeping track of @thread activity
120   * @dir:	pointer to the proc/irq/NN/name entry
121   */
122  struct irqaction {
123  	irq_handler_t		handler;
124  	void			*dev_id;
125  	void __percpu		*percpu_dev_id;
126  	struct irqaction	*next;
127  	irq_handler_t		thread_fn;
128  	struct task_struct	*thread;
129  	struct irqaction	*secondary;
130  	unsigned int		irq;
131  	unsigned int		flags;
132  	unsigned long		thread_flags;
133  	unsigned long		thread_mask;
134  	const char		*name;
135  	struct proc_dir_entry	*dir;
136  } ____cacheline_internodealigned_in_smp;
137  
138  extern irqreturn_t no_action(int cpl, void *dev_id);
139  
140  /*
141   * If a (PCI) device interrupt is not connected we set dev->irq to
142   * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
143   * can distingiush that case from other error returns.
144   *
145   * 0x80000000 is guaranteed to be outside the available range of interrupts
146   * and easy to distinguish from other possible incorrect values.
147   */
148  #define IRQ_NOTCONNECTED	(1U << 31)
149  
150  extern int __must_check
151  request_threaded_irq(unsigned int irq, irq_handler_t handler,
152  		     irq_handler_t thread_fn,
153  		     unsigned long flags, const char *name, void *dev);
154  
155  /**
156   * request_irq - Add a handler for an interrupt line
157   * @irq:	The interrupt line to allocate
158   * @handler:	Function to be called when the IRQ occurs.
159   *		Primary handler for threaded interrupts
160   *		If NULL, the default primary handler is installed
161   * @flags:	Handling flags
162   * @name:	Name of the device generating this interrupt
163   * @dev:	A cookie passed to the handler function
164   *
165   * This call allocates an interrupt and establishes a handler; see
166   * the documentation for request_threaded_irq() for details.
167   */
168  static inline int __must_check
request_irq(unsigned int irq,irq_handler_t handler,unsigned long flags,const char * name,void * dev)169  request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
170  	    const char *name, void *dev)
171  {
172  	return request_threaded_irq(irq, handler, NULL, flags | IRQF_COND_ONESHOT, name, dev);
173  }
174  
175  extern int __must_check
176  request_any_context_irq(unsigned int irq, irq_handler_t handler,
177  			unsigned long flags, const char *name, void *dev_id);
178  
179  extern int __must_check
180  __request_percpu_irq(unsigned int irq, irq_handler_t handler,
181  		     unsigned long flags, const char *devname,
182  		     void __percpu *percpu_dev_id);
183  
184  extern int __must_check
185  request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags,
186  	    const char *name, void *dev);
187  
188  static inline int __must_check
request_percpu_irq(unsigned int irq,irq_handler_t handler,const char * devname,void __percpu * percpu_dev_id)189  request_percpu_irq(unsigned int irq, irq_handler_t handler,
190  		   const char *devname, void __percpu *percpu_dev_id)
191  {
192  	return __request_percpu_irq(irq, handler, 0,
193  				    devname, percpu_dev_id);
194  }
195  
196  extern int __must_check
197  request_percpu_nmi(unsigned int irq, irq_handler_t handler,
198  		   const char *devname, void __percpu *dev);
199  
200  extern const void *free_irq(unsigned int, void *);
201  extern void free_percpu_irq(unsigned int, void __percpu *);
202  
203  extern const void *free_nmi(unsigned int irq, void *dev_id);
204  extern void free_percpu_nmi(unsigned int irq, void __percpu *percpu_dev_id);
205  
206  struct device;
207  
208  extern int __must_check
209  devm_request_threaded_irq(struct device *dev, unsigned int irq,
210  			  irq_handler_t handler, irq_handler_t thread_fn,
211  			  unsigned long irqflags, const char *devname,
212  			  void *dev_id);
213  
214  static inline int __must_check
devm_request_irq(struct device * dev,unsigned int irq,irq_handler_t handler,unsigned long irqflags,const char * devname,void * dev_id)215  devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
216  		 unsigned long irqflags, const char *devname, void *dev_id)
217  {
218  	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
219  					 devname, dev_id);
220  }
221  
222  extern int __must_check
223  devm_request_any_context_irq(struct device *dev, unsigned int irq,
224  		 irq_handler_t handler, unsigned long irqflags,
225  		 const char *devname, void *dev_id);
226  
227  extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
228  
229  bool irq_has_action(unsigned int irq);
230  extern void disable_irq_nosync(unsigned int irq);
231  extern bool disable_hardirq(unsigned int irq);
232  extern void disable_irq(unsigned int irq);
233  extern void disable_percpu_irq(unsigned int irq);
234  extern void enable_irq(unsigned int irq);
235  extern void enable_percpu_irq(unsigned int irq, unsigned int type);
236  extern bool irq_percpu_is_enabled(unsigned int irq);
237  extern void irq_wake_thread(unsigned int irq, void *dev_id);
238  
239  DEFINE_LOCK_GUARD_1(disable_irq, int,
240  		    disable_irq(*_T->lock), enable_irq(*_T->lock))
241  
242  extern void disable_nmi_nosync(unsigned int irq);
243  extern void disable_percpu_nmi(unsigned int irq);
244  extern void enable_nmi(unsigned int irq);
245  extern void enable_percpu_nmi(unsigned int irq, unsigned int type);
246  extern int prepare_percpu_nmi(unsigned int irq);
247  extern void teardown_percpu_nmi(unsigned int irq);
248  
249  extern int irq_inject_interrupt(unsigned int irq);
250  
251  /* The following three functions are for the core kernel use only. */
252  extern void suspend_device_irqs(void);
253  extern void resume_device_irqs(void);
254  extern void rearm_wake_irq(unsigned int irq);
255  
256  /**
257   * struct irq_affinity_notify - context for notification of IRQ affinity changes
258   * @irq:		Interrupt to which notification applies
259   * @kref:		Reference count, for internal use
260   * @work:		Work item, for internal use
261   * @notify:		Function to be called on change.  This will be
262   *			called in process context.
263   * @release:		Function to be called on release.  This will be
264   *			called in process context.  Once registered, the
265   *			structure must only be freed when this function is
266   *			called or later.
267   */
268  struct irq_affinity_notify {
269  	unsigned int irq;
270  	struct kref kref;
271  	struct work_struct work;
272  	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
273  	void (*release)(struct kref *ref);
274  };
275  
276  #define	IRQ_AFFINITY_MAX_SETS  4
277  
278  /**
279   * struct irq_affinity - Description for automatic irq affinity assignments
280   * @pre_vectors:	Don't apply affinity to @pre_vectors at beginning of
281   *			the MSI(-X) vector space
282   * @post_vectors:	Don't apply affinity to @post_vectors at end of
283   *			the MSI(-X) vector space
284   * @nr_sets:		The number of interrupt sets for which affinity
285   *			spreading is required
286   * @set_size:		Array holding the size of each interrupt set
287   * @calc_sets:		Callback for calculating the number and size
288   *			of interrupt sets
289   * @priv:		Private data for usage by @calc_sets, usually a
290   *			pointer to driver/device specific data.
291   */
292  struct irq_affinity {
293  	unsigned int	pre_vectors;
294  	unsigned int	post_vectors;
295  	unsigned int	nr_sets;
296  	unsigned int	set_size[IRQ_AFFINITY_MAX_SETS];
297  	void		(*calc_sets)(struct irq_affinity *, unsigned int nvecs);
298  	void		*priv;
299  };
300  
301  /**
302   * struct irq_affinity_desc - Interrupt affinity descriptor
303   * @mask:	cpumask to hold the affinity assignment
304   * @is_managed: 1 if the interrupt is managed internally
305   */
306  struct irq_affinity_desc {
307  	struct cpumask	mask;
308  	unsigned int	is_managed : 1;
309  };
310  
311  #if defined(CONFIG_SMP)
312  
313  extern cpumask_var_t irq_default_affinity;
314  
315  extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
316  extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask);
317  
318  extern int irq_can_set_affinity(unsigned int irq);
319  extern int irq_select_affinity(unsigned int irq);
320  
321  extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
322  				     bool setaffinity);
323  
324  /**
325   * irq_update_affinity_hint - Update the affinity hint
326   * @irq:	Interrupt to update
327   * @m:		cpumask pointer (NULL to clear the hint)
328   *
329   * Updates the affinity hint, but does not change the affinity of the interrupt.
330   */
331  static inline int
irq_update_affinity_hint(unsigned int irq,const struct cpumask * m)332  irq_update_affinity_hint(unsigned int irq, const struct cpumask *m)
333  {
334  	return __irq_apply_affinity_hint(irq, m, false);
335  }
336  
337  /**
338   * irq_set_affinity_and_hint - Update the affinity hint and apply the provided
339   *			     cpumask to the interrupt
340   * @irq:	Interrupt to update
341   * @m:		cpumask pointer (NULL to clear the hint)
342   *
343   * Updates the affinity hint and if @m is not NULL it applies it as the
344   * affinity of that interrupt.
345   */
346  static inline int
irq_set_affinity_and_hint(unsigned int irq,const struct cpumask * m)347  irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m)
348  {
349  	return __irq_apply_affinity_hint(irq, m, true);
350  }
351  
352  /*
353   * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint()
354   * instead.
355   */
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)356  static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
357  {
358  	return irq_set_affinity_and_hint(irq, m);
359  }
360  
361  extern int irq_update_affinity_desc(unsigned int irq,
362  				    struct irq_affinity_desc *affinity);
363  
364  extern int
365  irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
366  
367  struct irq_affinity_desc *
368  irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd);
369  
370  unsigned int irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
371  				       const struct irq_affinity *affd);
372  
373  #else /* CONFIG_SMP */
374  
irq_set_affinity(unsigned int irq,const struct cpumask * m)375  static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
376  {
377  	return -EINVAL;
378  }
379  
irq_force_affinity(unsigned int irq,const struct cpumask * cpumask)380  static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
381  {
382  	return 0;
383  }
384  
irq_can_set_affinity(unsigned int irq)385  static inline int irq_can_set_affinity(unsigned int irq)
386  {
387  	return 0;
388  }
389  
irq_select_affinity(unsigned int irq)390  static inline int irq_select_affinity(unsigned int irq)  { return 0; }
391  
irq_update_affinity_hint(unsigned int irq,const struct cpumask * m)392  static inline int irq_update_affinity_hint(unsigned int irq,
393  					   const struct cpumask *m)
394  {
395  	return -EINVAL;
396  }
397  
irq_set_affinity_and_hint(unsigned int irq,const struct cpumask * m)398  static inline int irq_set_affinity_and_hint(unsigned int irq,
399  					    const struct cpumask *m)
400  {
401  	return -EINVAL;
402  }
403  
irq_set_affinity_hint(unsigned int irq,const struct cpumask * m)404  static inline int irq_set_affinity_hint(unsigned int irq,
405  					const struct cpumask *m)
406  {
407  	return -EINVAL;
408  }
409  
irq_update_affinity_desc(unsigned int irq,struct irq_affinity_desc * affinity)410  static inline int irq_update_affinity_desc(unsigned int irq,
411  					   struct irq_affinity_desc *affinity)
412  {
413  	return -EINVAL;
414  }
415  
416  static inline int
irq_set_affinity_notifier(unsigned int irq,struct irq_affinity_notify * notify)417  irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
418  {
419  	return 0;
420  }
421  
422  static inline struct irq_affinity_desc *
irq_create_affinity_masks(unsigned int nvec,struct irq_affinity * affd)423  irq_create_affinity_masks(unsigned int nvec, struct irq_affinity *affd)
424  {
425  	return NULL;
426  }
427  
428  static inline unsigned int
irq_calc_affinity_vectors(unsigned int minvec,unsigned int maxvec,const struct irq_affinity * affd)429  irq_calc_affinity_vectors(unsigned int minvec, unsigned int maxvec,
430  			  const struct irq_affinity *affd)
431  {
432  	return maxvec;
433  }
434  
435  #endif /* CONFIG_SMP */
436  
437  /*
438   * Special lockdep variants of irq disabling/enabling.
439   * These should be used for locking constructs that
440   * know that a particular irq context which is disabled,
441   * and which is the only irq-context user of a lock,
442   * that it's safe to take the lock in the irq-disabled
443   * section without disabling hardirqs.
444   *
445   * On !CONFIG_LOCKDEP they are equivalent to the normal
446   * irq disable/enable methods.
447   */
disable_irq_nosync_lockdep(unsigned int irq)448  static inline void disable_irq_nosync_lockdep(unsigned int irq)
449  {
450  	disable_irq_nosync(irq);
451  #ifdef CONFIG_LOCKDEP
452  	local_irq_disable();
453  #endif
454  }
455  
disable_irq_nosync_lockdep_irqsave(unsigned int irq,unsigned long * flags)456  static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
457  {
458  	disable_irq_nosync(irq);
459  #ifdef CONFIG_LOCKDEP
460  	local_irq_save(*flags);
461  #endif
462  }
463  
disable_irq_lockdep(unsigned int irq)464  static inline void disable_irq_lockdep(unsigned int irq)
465  {
466  	disable_irq(irq);
467  #ifdef CONFIG_LOCKDEP
468  	local_irq_disable();
469  #endif
470  }
471  
enable_irq_lockdep(unsigned int irq)472  static inline void enable_irq_lockdep(unsigned int irq)
473  {
474  #ifdef CONFIG_LOCKDEP
475  	local_irq_enable();
476  #endif
477  	enable_irq(irq);
478  }
479  
enable_irq_lockdep_irqrestore(unsigned int irq,unsigned long * flags)480  static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
481  {
482  #ifdef CONFIG_LOCKDEP
483  	local_irq_restore(*flags);
484  #endif
485  	enable_irq(irq);
486  }
487  
488  /* IRQ wakeup (PM) control: */
489  extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
490  
enable_irq_wake(unsigned int irq)491  static inline int enable_irq_wake(unsigned int irq)
492  {
493  	return irq_set_irq_wake(irq, 1);
494  }
495  
disable_irq_wake(unsigned int irq)496  static inline int disable_irq_wake(unsigned int irq)
497  {
498  	return irq_set_irq_wake(irq, 0);
499  }
500  
501  /*
502   * irq_get_irqchip_state/irq_set_irqchip_state specific flags
503   */
504  enum irqchip_irq_state {
505  	IRQCHIP_STATE_PENDING,		/* Is interrupt pending? */
506  	IRQCHIP_STATE_ACTIVE,		/* Is interrupt in progress? */
507  	IRQCHIP_STATE_MASKED,		/* Is interrupt masked? */
508  	IRQCHIP_STATE_LINE_LEVEL,	/* Is IRQ line high? */
509  };
510  
511  extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
512  				 bool *state);
513  extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
514  				 bool state);
515  
516  #ifdef CONFIG_IRQ_FORCED_THREADING
517  # ifdef CONFIG_PREEMPT_RT
518  #  define force_irqthreads()	(true)
519  # else
520  DECLARE_STATIC_KEY_FALSE(force_irqthreads_key);
521  #  define force_irqthreads()	(static_branch_unlikely(&force_irqthreads_key))
522  # endif
523  #else
524  #define force_irqthreads()	(false)
525  #endif
526  
527  #ifndef local_softirq_pending
528  
529  #ifndef local_softirq_pending_ref
530  #define local_softirq_pending_ref irq_stat.__softirq_pending
531  #endif
532  
533  #define local_softirq_pending()	(__this_cpu_read(local_softirq_pending_ref))
534  #define set_softirq_pending(x)	(__this_cpu_write(local_softirq_pending_ref, (x)))
535  #define or_softirq_pending(x)	(__this_cpu_or(local_softirq_pending_ref, (x)))
536  
537  #endif /* local_softirq_pending */
538  
539  /* Some architectures might implement lazy enabling/disabling of
540   * interrupts. In some cases, such as stop_machine, we might want
541   * to ensure that after a local_irq_disable(), interrupts have
542   * really been disabled in hardware. Such architectures need to
543   * implement the following hook.
544   */
545  #ifndef hard_irq_disable
546  #define hard_irq_disable()	do { } while(0)
547  #endif
548  
549  /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
550     frequency threaded job scheduling. For almost all the purposes
551     tasklets are more than enough. F.e. all serial device BHs et
552     al. should be converted to tasklets, not to softirqs.
553   */
554  
555  enum
556  {
557  	HI_SOFTIRQ=0,
558  	TIMER_SOFTIRQ,
559  	NET_TX_SOFTIRQ,
560  	NET_RX_SOFTIRQ,
561  	BLOCK_SOFTIRQ,
562  	IRQ_POLL_SOFTIRQ,
563  	TASKLET_SOFTIRQ,
564  	SCHED_SOFTIRQ,
565  	HRTIMER_SOFTIRQ,
566  	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
567  
568  	NR_SOFTIRQS
569  };
570  
571  /*
572   * The following vectors can be safely ignored after ksoftirqd is parked:
573   *
574   * _ RCU:
575   * 	1) rcutree_migrate_callbacks() migrates the queue.
576   * 	2) rcutree_report_cpu_dead() reports the final quiescent states.
577   *
578   * _ IRQ_POLL: irq_poll_cpu_dead() migrates the queue
579   *
580   * _ (HR)TIMER_SOFTIRQ: (hr)timers_dead_cpu() migrates the queue
581   */
582  #define SOFTIRQ_HOTPLUG_SAFE_MASK (BIT(TIMER_SOFTIRQ) | BIT(IRQ_POLL_SOFTIRQ) |\
583  				   BIT(HRTIMER_SOFTIRQ) | BIT(RCU_SOFTIRQ))
584  
585  
586  /* map softirq index to softirq name. update 'softirq_to_name' in
587   * kernel/softirq.c when adding a new softirq.
588   */
589  extern const char * const softirq_to_name[NR_SOFTIRQS];
590  
591  /* softirq mask and active fields moved to irq_cpustat_t in
592   * asm/hardirq.h to get better cache usage.  KAO
593   */
594  
595  struct softirq_action
596  {
597  	void	(*action)(void);
598  };
599  
600  asmlinkage void do_softirq(void);
601  asmlinkage void __do_softirq(void);
602  
603  #ifdef CONFIG_PREEMPT_RT
604  extern void do_softirq_post_smp_call_flush(unsigned int was_pending);
605  #else
do_softirq_post_smp_call_flush(unsigned int unused)606  static inline void do_softirq_post_smp_call_flush(unsigned int unused)
607  {
608  	do_softirq();
609  }
610  #endif
611  
612  extern void open_softirq(int nr, void (*action)(void));
613  extern void softirq_init(void);
614  extern void __raise_softirq_irqoff(unsigned int nr);
615  
616  extern void raise_softirq_irqoff(unsigned int nr);
617  extern void raise_softirq(unsigned int nr);
618  
619  DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
620  
this_cpu_ksoftirqd(void)621  static inline struct task_struct *this_cpu_ksoftirqd(void)
622  {
623  	return this_cpu_read(ksoftirqd);
624  }
625  
626  /* Tasklets --- multithreaded analogue of BHs.
627  
628     This API is deprecated. Please consider using threaded IRQs instead:
629     https://lore.kernel.org/lkml/20200716081538.2sivhkj4hcyrusem@linutronix.de
630  
631     Main feature differing them of generic softirqs: tasklet
632     is running only on one CPU simultaneously.
633  
634     Main feature differing them of BHs: different tasklets
635     may be run simultaneously on different CPUs.
636  
637     Properties:
638     * If tasklet_schedule() is called, then tasklet is guaranteed
639       to be executed on some cpu at least once after this.
640     * If the tasklet is already scheduled, but its execution is still not
641       started, it will be executed only once.
642     * If this tasklet is already running on another CPU (or schedule is called
643       from tasklet itself), it is rescheduled for later.
644     * Tasklet is strictly serialized wrt itself, but not
645       wrt another tasklets. If client needs some intertask synchronization,
646       he makes it with spinlocks.
647   */
648  
649  struct tasklet_struct
650  {
651  	struct tasklet_struct *next;
652  	unsigned long state;
653  	atomic_t count;
654  	bool use_callback;
655  	union {
656  		void (*func)(unsigned long data);
657  		void (*callback)(struct tasklet_struct *t);
658  	};
659  	unsigned long data;
660  };
661  
662  #define DECLARE_TASKLET(name, _callback)		\
663  struct tasklet_struct name = {				\
664  	.count = ATOMIC_INIT(0),			\
665  	.callback = _callback,				\
666  	.use_callback = true,				\
667  }
668  
669  #define DECLARE_TASKLET_DISABLED(name, _callback)	\
670  struct tasklet_struct name = {				\
671  	.count = ATOMIC_INIT(1),			\
672  	.callback = _callback,				\
673  	.use_callback = true,				\
674  }
675  
676  #define from_tasklet(var, callback_tasklet, tasklet_fieldname)	\
677  	container_of(callback_tasklet, typeof(*var), tasklet_fieldname)
678  
679  #define DECLARE_TASKLET_OLD(name, _func)		\
680  struct tasklet_struct name = {				\
681  	.count = ATOMIC_INIT(0),			\
682  	.func = _func,					\
683  }
684  
685  #define DECLARE_TASKLET_DISABLED_OLD(name, _func)	\
686  struct tasklet_struct name = {				\
687  	.count = ATOMIC_INIT(1),			\
688  	.func = _func,					\
689  }
690  
691  enum
692  {
693  	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
694  	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
695  };
696  
697  #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
tasklet_trylock(struct tasklet_struct * t)698  static inline int tasklet_trylock(struct tasklet_struct *t)
699  {
700  	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
701  }
702  
703  void tasklet_unlock(struct tasklet_struct *t);
704  void tasklet_unlock_wait(struct tasklet_struct *t);
705  void tasklet_unlock_spin_wait(struct tasklet_struct *t);
706  
707  #else
tasklet_trylock(struct tasklet_struct * t)708  static inline int tasklet_trylock(struct tasklet_struct *t) { return 1; }
tasklet_unlock(struct tasklet_struct * t)709  static inline void tasklet_unlock(struct tasklet_struct *t) { }
tasklet_unlock_wait(struct tasklet_struct * t)710  static inline void tasklet_unlock_wait(struct tasklet_struct *t) { }
tasklet_unlock_spin_wait(struct tasklet_struct * t)711  static inline void tasklet_unlock_spin_wait(struct tasklet_struct *t) { }
712  #endif
713  
714  extern void __tasklet_schedule(struct tasklet_struct *t);
715  
tasklet_schedule(struct tasklet_struct * t)716  static inline void tasklet_schedule(struct tasklet_struct *t)
717  {
718  	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
719  		__tasklet_schedule(t);
720  }
721  
722  extern void __tasklet_hi_schedule(struct tasklet_struct *t);
723  
tasklet_hi_schedule(struct tasklet_struct * t)724  static inline void tasklet_hi_schedule(struct tasklet_struct *t)
725  {
726  	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
727  		__tasklet_hi_schedule(t);
728  }
729  
tasklet_disable_nosync(struct tasklet_struct * t)730  static inline void tasklet_disable_nosync(struct tasklet_struct *t)
731  {
732  	atomic_inc(&t->count);
733  	smp_mb__after_atomic();
734  }
735  
736  /*
737   * Do not use in new code. Disabling tasklets from atomic contexts is
738   * error prone and should be avoided.
739   */
tasklet_disable_in_atomic(struct tasklet_struct * t)740  static inline void tasklet_disable_in_atomic(struct tasklet_struct *t)
741  {
742  	tasklet_disable_nosync(t);
743  	tasklet_unlock_spin_wait(t);
744  	smp_mb();
745  }
746  
tasklet_disable(struct tasklet_struct * t)747  static inline void tasklet_disable(struct tasklet_struct *t)
748  {
749  	tasklet_disable_nosync(t);
750  	tasklet_unlock_wait(t);
751  	smp_mb();
752  }
753  
tasklet_enable(struct tasklet_struct * t)754  static inline void tasklet_enable(struct tasklet_struct *t)
755  {
756  	smp_mb__before_atomic();
757  	atomic_dec(&t->count);
758  }
759  
760  extern void tasklet_kill(struct tasklet_struct *t);
761  extern void tasklet_init(struct tasklet_struct *t,
762  			 void (*func)(unsigned long), unsigned long data);
763  extern void tasklet_setup(struct tasklet_struct *t,
764  			  void (*callback)(struct tasklet_struct *));
765  
766  /*
767   * Autoprobing for irqs:
768   *
769   * probe_irq_on() and probe_irq_off() provide robust primitives
770   * for accurate IRQ probing during kernel initialization.  They are
771   * reasonably simple to use, are not "fooled" by spurious interrupts,
772   * and, unlike other attempts at IRQ probing, they do not get hung on
773   * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
774   *
775   * For reasonably foolproof probing, use them as follows:
776   *
777   * 1. clear and/or mask the device's internal interrupt.
778   * 2. sti();
779   * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
780   * 4. enable the device and cause it to trigger an interrupt.
781   * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
782   * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
783   * 7. service the device to clear its pending interrupt.
784   * 8. loop again if paranoia is required.
785   *
786   * probe_irq_on() returns a mask of allocated irq's.
787   *
788   * probe_irq_off() takes the mask as a parameter,
789   * and returns the irq number which occurred,
790   * or zero if none occurred, or a negative irq number
791   * if more than one irq occurred.
792   */
793  
794  #if !defined(CONFIG_GENERIC_IRQ_PROBE)
probe_irq_on(void)795  static inline unsigned long probe_irq_on(void)
796  {
797  	return 0;
798  }
probe_irq_off(unsigned long val)799  static inline int probe_irq_off(unsigned long val)
800  {
801  	return 0;
802  }
probe_irq_mask(unsigned long val)803  static inline unsigned int probe_irq_mask(unsigned long val)
804  {
805  	return 0;
806  }
807  #else
808  extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
809  extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
810  extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
811  #endif
812  
813  #ifdef CONFIG_PROC_FS
814  /* Initialize /proc/irq/ */
815  extern void init_irq_proc(void);
816  #else
init_irq_proc(void)817  static inline void init_irq_proc(void)
818  {
819  }
820  #endif
821  
822  #ifdef CONFIG_IRQ_TIMINGS
823  void irq_timings_enable(void);
824  void irq_timings_disable(void);
825  u64 irq_timings_next_event(u64 now);
826  #endif
827  
828  struct seq_file;
829  int show_interrupts(struct seq_file *p, void *v);
830  int arch_show_interrupts(struct seq_file *p, int prec);
831  
832  extern int early_irq_init(void);
833  extern int arch_probe_nr_irqs(void);
834  extern int arch_early_irq_init(void);
835  
836  /*
837   * We want to know which function is an entrypoint of a hardirq or a softirq.
838   */
839  #ifndef __irq_entry
840  # define __irq_entry	 __section(".irqentry.text")
841  #endif
842  
843  #define __softirq_entry  __section(".softirqentry.text")
844  
845  #endif
846